Efficient penetration of the basal plane (0001) face of ice Ih by HF at Ts=150 K: Dependence on incidence energy, incidence angle, and rotational energy

Classical trajectory simulations are carried out to investigate the influence of incidence energy, incidence angle, and rotational energy on the penetration of the basal plane (0001) face of ice Ih by HF at a surface temperature (Ts) of 150 K. The interaction of HF with ice is modelled by pair interactions, with the pair potential fitted to ab initio (Hartree–Fock+MP2) calculations. The penetration of ice by HF occurs already at very low incidence energies, viz., Ei⩾20 kJ mol−1. This is much lower than the threshold incidence energy obtained for penetration of ice by HCl (Ei≈96.5 kJ mol−1); the calculated average barrier to penetration of ice by HF is 16.0 kJ mol−1 and is much lower than that previously reported for HCl. As was the case for HCl, penetration of ice by HF decreases with decreasing incidence energy and increasing incidence angle. Though in general, the penetration probability is independent of the molecule’s initial rotational energy, penetration beyond the second bilayer (deep penetration) ...